The present invention relates to a drive machine and, more particularly, to an electric drive machine.
There has been manufactured a spring-driven nailing machine which lifts a spring-impelled plunger against restoration force of a spring and subsequently releases the thus-lifted plunger, to thus drive a nail into a material to be nailed (hereinafter called a “target material”) by the accelerated plunger. As described in Patent Document 1, the plunger is lifted by a built-in motor of a tool, thereby lessening efforts to lift the plunger.
Specifically, a plurality of rotary gears synchronously driven by a motor via a reduction gear are disposed opposite the motor. Drive pins fixed to positions decentered from the rotational center of the respective rotary gears are brought into engagement with an engagement section provided on the plunger impelled by a spring, thereby lifting the plunger upward by a predetermined amount of stroke against restoration force of the spring. Therefore, when the plunger is lifted by one rotary gear, the plunger can be lifted by the maximum amount of stroke corresponding to the diameter of the rotary gear. When the predetermined stroke of the plunger has become greater, the diameter of the rotary gear or the number of rotary gears is increased. (See JP-A-9-295283)